Probing supramolecular complexation of the drug benserazide hydrochloride with hydroxypropyl-β-cyclodextrin by experimental and computational studies

Abstract

Herein, we explore the supramolecular complexation of Benserazide hydrochloride (BNZ) with Hydroxypropyl-β-cyclodextrin (HP-β-CD) in an aqueous medium by means of UV–visible, surface tension, FT-IR, 1H NMR, 2D ROESY, DSC, PXRD and molecular docking study. These studies suggest the effective complexation of BNZ with HP-β-CD resulting in the formation of BNZ-HP-β-CD complex. Surface tension study and Job's plot confirm 1:1 stoichiometry of BNZ-HP-β-CD complex. FT-IR, 1H NMR and 2D ROESY studies suggest the possible binding mode of BNZ into the cavity of HP-β-CD. The binding constant (Ka) of BNZ-HP-β-CD complex indicates the affinity of HP-β-CD for BNZ. The estimated negative free energy of binding reveals that the complexation process is thermodynamically feasible. PXRD analysis confirms the formation of BNZ-HP-β-CD inclusion complex. DSC analysis shows the enhancement in the thermal stability of BNZ after complexation with HP-β-CD. The molecular docking study introduces the most stable binding orientation of BNZ within the cavity of HP-β-CD. The complex expresses better cytotoxic effect than free BNZ on both lung carcinomic A549 cell line and ovarian SKOV3 cancer cell line. Furthermore, the considerable improvement in the antioxidant activity of BNZ is registered after encapsulation.